In this Oct. 9, 2007 file photo, radio telescopes of the Allen Telescope Array are seen in Hat Creek, Calif. Astronomers at the SETI Institute in Northern California say a steep drop in state and federal funds has forced the shutdown of a key program to search for extraterrestrial life. Dozens of radio dishes that make up the Allen Telescope Array in the mountains of far Northern California have scanned deep space since 2007 for alien signals.

State and federal budget cuts have forced astronomers operating the 42 telescopes at UC Berkeley's famed Hat Creek Radio Astronomy Laboratory to suspend their search for signals from extraterrestrial civilizations.

SETI Institute astronomer Jill Tarter said Tuesday the entire laboratory in the remote Lassen National Forest near Redding is being "placed in hibernation" because $2.5 million in funds from the National Science Foundation and from UC's astronomy budget have dried up.

Other money expected from the Air Force for tracking orbital debris and satellites in space is awaiting congressional budget action, said Jack Welch, an astronomy professor at the UC Berkeley graduate school and a former director of the radio astronomy laboratory.

The suspension is a blow to the SETI Institute, whose astronomers have been seeking signs of life in distant space for more than 30 years. In recent years, the telescopes have cost about $1.5 million a year to operate, and another $1 million has gone to the SETI search, Tarter said.

The half-dozen UC scientists who use the Hat Creek telescopes remotely from their on-campus office computers can move their research efforts to radio telescope sites elsewhere, "but only with difficulty," said Leo Blitz, the lab's current director.

Leaders of NASA's Kepler spacecraft have detected 1,235 distant stars that might hold earthlike planets in "habitable zones," and the craft is now scanning 146,000 "candidate stars" that might also hold such planets.

Tarter said SETI astronomers who have joined the hunt with the telescopes at Hat Creek will have to cancel their work on the Kepler project.

"The Kepler mission for the first time has made people really understand that planets far away really might be very much like Earth and hold life - perhaps even civilizations - and that's what the SETI search is all about," Tarter said.

The telescopes and all the other equipment at the Hat Creek laboratory are being held in a "safe mode," ready to be started up again if money ever becomes available, said Tom Pierson, executive director of the SETI Institute.

"We're hoping to raise at least $5 million to return to full operations and assure the future of the telescopes," Tarter said.

The Allen Telescope Array was initially financed with an $11 million grant from Microsoft co-founder Paul Allen. It is planned to include a total of 350 6-meter telescopes, all arrayed in a pattern and operated simultaneously to scan across distant space.

Then advanced computers at the lab would analyze apparently random radio noise that might just turn out to be alien signals from unknown beings on distant planets that have yet to be found.